Add generic streaming interpreter with configurable sources/audio

- Add stream_sexp_generic.py: fully generic sexp interpreter
- Add streaming primitives for video sources and audio analysis
- Add config system for external sources and audio files
- Add templates for reusable scans and macros
- Fix video/audio stream mapping in file output
- Add dynamic source cycling based on sources array length
- Remove old Python effect files (migrated to sexp)
- Update sexp effects to use namespaced primitives

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sexp_effects/effects/flip.sexp

@@ -1,4 +1,5 @@
 ;; Flip effect - flips image horizontally or vertically
+(require-primitives "geometry")
 
 (define-effect flip
   :params (
@@ -7,9 +8,9 @@
   )
   (let ((result frame))
     (if horizontal
-        (set! result (flip-h result))
+        (set! result (geometry:flip-img result "horizontal"))
         nil)
     (if vertical
-        (set! result (flip-v result))
+        (set! result (geometry:flip-img result "vertical"))
         nil)
     result))